In certain industries, the unwanted failure of electrical equipment due to the loss of power cannot be tolerated. For instance, because people depend on their telephones to communicate in emergency situations, telecommunications systems must maintain continuity of service even in the face of power failures. In order to accomplish this, power must be provided in an uninterrupted fashion to the equipment in the telecommunications system. UPS systems are very useful in helping to prevent the unwanted failure of telecommunications equipment due to the loss of power.
In general, there are two primary methods of providing uninterrupted input power to a telecommunications system. One type of system is a direct current (“DC”) power system (referred to herein as a “DC system”). In a DC system, power for the telecommunications equipment is provided by the local utility, which in most instances is alternating current (“AC”) power. The AC power provided by the local utility is rectified into DC and applied across batteries connected to the telephone equipment load. The DC provides trickle charge to the batteries keeping them in a fully charged condition. The DC also recharges the batteries after the batteries have been used during an AC power outage.
The other primary method of providing uninterrupted input power to a telecommunications system is an AC power system (referred to herein as an “AC system”). In an AC system, power for the telecommunications equipment is provided by the local utility, which in most instances is AC power. AC power is rectified into DC by a single rectifier. The rectified DC is then fed to a battery string for trickle charge and recharge purposes. An inverter circuit is utilized to transform the DC into AC. When there is a loss of utility power, the batteries become the prime energy source. The output of the inverter circuit is distributed to equipment requiring continuity of AC input power.
Although AC and DC systems have long been the primary choice for providing uninterruptible power to telecommunications equipment, these systems do suffer from several significant drawbacks. In particular, because AC systems only include a single rectifier and inverter, loss of either of these units can result in loss of UPS output. Both AC and DC systems also require significant floor space and generate considerable floor weight loads as a result of the weight of their batteries. Moreover, these previous systems require complex and expensive power cable and associated labor to install.
It is with respect to these considerations and others that the embodiments of the present invention are made.